Mitsubishi Repair: Starter, mighty max, flywheel

Question
I have a 91 Mighty Max pick up.  That was given to me.  The problem is you take the starter off and it works fine.  Put the starter on the truck.  The starter does not engage.  All you get is the solenoid to click.  I changed the battery with no help.  Any ideas?

Answer
Joe,
If I understand you correctly, you removed the starter from your truck, you hooked the starter up to a battery, and it engages.  But when you install the starter back into the truck, the starter will not turn.  I hope I got that right.

There could be a couple possible problems.  One, your flywheel may be stuck.  If that flywheel is stuck and won't turn, you most likely will not hear the starter crank over either.  Two, your starter may be too weak to handle the load to turn the flywheel to start the engine.  In that case, your starter can still appear to be working when no load is applied to it when detached from the car.  Or third, your battery is too weak turn the starter over when a load is applied to it.  Make sure the battery is fully charged.  I hope that gives you some clues.
Good luck!